package net.minecraft.entity.ai;

import java.util.Random;
import net.minecraft.entity.EntityCreature;
import net.minecraft.util.BlockPos;
import net.minecraft.util.MathHelper;
import net.minecraft.util.Vec3;

public class RandomPositionGenerator {
	/**
	 * used to store a driection when the user passes a point to move towards or
	 * away from. WARNING: NEVER THREAD SAFE. MULTIPLE findTowards and findAway
	 * calls, will share this var
	 */
	private static Vec3 staticVector = new Vec3(0.0D, 0.0D, 0.0D);

	/**
	 * finds a random target within par1(x,z) and par2 (y) blocks
	 */
	public static Vec3 findRandomTarget(EntityCreature entitycreatureIn, int xz, int y) {
		return findRandomTargetBlock(entitycreatureIn, xz, y, (Vec3) null);
	}

	/**
	 * finds a random target within par1(x,z) and par2 (y) blocks in the direction
	 * of the point par3
	 */
	public static Vec3 findRandomTargetBlockTowards(EntityCreature entitycreatureIn, int xz, int y, Vec3 targetVec3) {
		staticVector = targetVec3.subtract(entitycreatureIn.posX, entitycreatureIn.posY, entitycreatureIn.posZ);
		return findRandomTargetBlock(entitycreatureIn, xz, y, staticVector);
	}

	/**
	 * finds a random target within par1(x,z) and par2 (y) blocks in the reverse
	 * direction of the point par3
	 */
	public static Vec3 findRandomTargetBlockAwayFrom(EntityCreature entitycreatureIn, int xz, int y, Vec3 targetVec3) {
		staticVector = (new Vec3(entitycreatureIn.posX, entitycreatureIn.posY, entitycreatureIn.posZ))
				.subtract(targetVec3);
		return findRandomTargetBlock(entitycreatureIn, xz, y, staticVector);
	}

	/**
	 * searches 10 blocks at random in a within par1(x,z) and par2 (y) distance,
	 * ignores those not in the direction of par3Vec3, then points to the tile for
	 * which creature.getBlockPathWeight returns the highest number
	 */
	private static Vec3 findRandomTargetBlock(EntityCreature entitycreatureIn, int xz, int y, Vec3 targetVec3) {
		Random random = entitycreatureIn.getRNG();
		boolean flag = false;
		int i = 0;
		int j = 0;
		int k = 0;
		float f = -99999.0F;
		boolean flag1;

		if (entitycreatureIn.hasHome()) {
			double d0 = entitycreatureIn.getHomePosition().distanceSq(
					(double) MathHelper.floor_double(entitycreatureIn.posX),
					(double) MathHelper.floor_double(entitycreatureIn.posY),
					(double) MathHelper.floor_double(entitycreatureIn.posZ)) + 4.0D;
			double d1 = (double) (entitycreatureIn.getMaximumHomeDistance() + (float) xz);
			flag1 = d0 < d1 * d1;
		} else {
			flag1 = false;
		}

		for (int j1 = 0; j1 < 10; ++j1) {
			int l = random.nextInt(2 * xz + 1) - xz;
			int k1 = random.nextInt(2 * y + 1) - y;
			int i1 = random.nextInt(2 * xz + 1) - xz;

			if (targetVec3 == null || (double) l * targetVec3.xCoord + (double) i1 * targetVec3.zCoord >= 0.0D) {
				if (entitycreatureIn.hasHome() && xz > 1) {
					BlockPos blockpos = entitycreatureIn.getHomePosition();

					if (entitycreatureIn.posX > (double) blockpos.getX()) {
						l -= random.nextInt(xz / 2);
					} else {
						l += random.nextInt(xz / 2);
					}

					if (entitycreatureIn.posZ > (double) blockpos.getZ()) {
						i1 -= random.nextInt(xz / 2);
					} else {
						i1 += random.nextInt(xz / 2);
					}
				}

				l = l + MathHelper.floor_double(entitycreatureIn.posX);
				k1 = k1 + MathHelper.floor_double(entitycreatureIn.posY);
				i1 = i1 + MathHelper.floor_double(entitycreatureIn.posZ);
				BlockPos blockpos1 = new BlockPos(l, k1, i1);

				if (!flag1 || entitycreatureIn.isWithinHomeDistanceFromPosition(blockpos1)) {
					float f1 = entitycreatureIn.getBlockPathWeight(blockpos1);

					if (f1 > f) {
						f = f1;
						i = l;
						j = k1;
						k = i1;
						flag = true;
					}
				}
			}
		}

		if (flag) {
			return new Vec3((double) i, (double) j, (double) k);
		} else {
			return null;
		}
	}
}
